Fenix5X+ simulator fails to download FIT workout data

The Fenix 5X+ simulator does not seem to be able to download workouts when running as 2.4.x or 3.0.x. The callback gets a response code 200 but null download data.

After this point our app shows a menu, and then selecting any option from that menu will hang the simulator hard.

Eclipse Oxygen.3a (4.7.3a), SDK 3.0.0-beta3, Windows 10 64bit.

Other simulators seem to be fine (including the 645M as both 2.4.x and 3.0.x)

The specific line of code is at

https://github.com/TrainAsONE/trainasone-connectiq/blob/c34e3be5ef41fb541cb9afdf505a435048b3d48c/source/Download.mc#L133

Thanks